Gage.



Patented J uly 25, 1916.

vA. MELDRUM,

GAGE.

APPLICATION FILED JUNE 22. i914.

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'unrrun srarns Para i 1- ALEXANDER MELDRUM, OF SYRACUSE, NEW YORILASSIGNOR TO THE L. S. STARRETT COMPANY, OF ATHOL, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

GAGE.

incenso.

Specification of Letters Patent.

Patented July 25, 1916.

To all 'w wm t may concern:

Be it known that I, ALEXANDER MELDRUM, a citizen of the United States, residing at Syracuse, county of Onondaga, State of New York, have invented certain new and useful Improvements in Grages7 of which the following is a specification.

This invention relates to instruments of precision and particularly to a gage for setting dividers. The need of an instrument which will permit the divider points to be v set to very fine adjustments has been long felt. To comply with the essential requirements of eXtreme accuracy of measurement and nicety of adjustment such an instrument should be capable of giving practically a micrometer reading.

To the end therefore of providing such an instrument I have devised my present invention. In it, I use a gage comprising two relatively rotatable members having related graduations adapted tocoact with each other and with a line inclined to the axis of rota. tion of the members on one of the members so as to give practically a micrometer reading in addition to the regular reading.

The construction and operation of my invention will be more fully disclosed in the specification which follows.

In the drawings I have shown as an illustrative embodiment a form of gage which has been found well adapted for the purposes intended and the requirements of manufacture.

Throughout specification and drawings like reference numerals are correspondingly applied, and in these drawings:

Figure l is an elevation of a gage constructed in accordance with my invention, Fig. 2 is a partial longitudinal section of the gage on an enlarged scale, and Fig. 3 is a development of the rotatable sleeve of the gage.

I have indicated at 1 a gage bar of any de- 'sired shape and length. As shown in Fig. 1

with each tenth division numbered. The

solid end of the bar is shouldered as indicated at 3 in Fig. 2 to provide an axial reduced stem A on which a graduated sleeve 5 is rotatably mounted. The sleeve 5 has an internal annular recess 6 about its inner end to reduce its bearing against the shoulder 3. The sleeve is seated against the shoulder 3 by a screw 7 threaded in the aXialbore 8 of the stem 4. A coil spring 9 encircling the stem a assists with the screw 7 to seat the sleeve against the shoulder with a yielding bearing. The spring 9 is confined in a cham ber l0 included between the head 11 of the screw 7 and the internal front wall 12 of a tubular extension 13 formed on the sleeve 5. The extension 13 is knurled externally to facilitate rotation of the sleeve. The sleeve 5 is graduated in any desired scale 111 having a definite relation to the graduations of the bar 1. A convenient graduation is seen in Fig. 3 wherein the sleeve is shown as divided circumferentially into twenty-five divisions with each fifth division numbered. Encircling the sleeve spirally is an indicated line 15 which cooperates with the graduations on the bar and sleeve to indicate the pitch. In this case, the line 15 indicates lone-fortieth pitch to the inch.

In use, one point of the dividers is placed in any of the divisions of the graduated scale bar and the other point at the graduated crossing of the pitch line of the sleeve. With the conventional scale shown in the drawing, this gives any division in thousandths in addition to the regular graduations on the scale bar and amounts to practically a micrometer reading.

Various modifications in the form and construction of the gage, in the scale shown and the distance indicated may obviously be resorted to if within the limits of the appended claims.

What I therefore claim and desire to secure by Letters Patent is:

1. A gage for setting dividers comprising a longitudinally graduated gage bar and a graduated sleeve, said bar and sleeve being relatively rotatable and yieldably seated against each other and a spiralpitch indication continuously about one of said members in, intersecting relation to the graduations thereof and cooperating with the graduations of the other member to set off dista'nces.

2. A gage comprising a longitudinally graduated gage bar, hollow for substantially its entire length and closed at one end having a reduced extension providing a bearing, a graduated sleeve rotatably mounted on said extension and yieldably seated against said closed end of the bar, and a pitch indication continuously about one of said members and coperating with the graduations of the other of saidk members to set oii1 distances.

3. A gage comprising a longitudinally graduated hollow gage bar having a closed end terminating in a reduced extension providing a bearing, a graduated sleeve rotatably mounted on said extension and 4yieldably seated against said closed end of the bar and a pitch indication spirally about one of said members and coperating with the graduations of the other of said members to set off distances.

4. A gage comprising a longitudinally graduated hollow gage bar having a closed end terminating in a reduced extension providing a. bearing, a graduated sleeve rotatably mounted on said extension, said extension having a threaded bore, a screw set up in said bore for seating the sleeve against the closed end of the bar and a spring associated with said screw and effective therewith to yieldably seat said sleeve against the gage bar.

5. A gage comprising a longitudinally graduated hollow gagebar having a closed end terminating in a reduced extension providing a bearing, a graduated sleeve rotatably mounted on said extension, said extension having a threaded bore, a screw set up in said bore for seating the sleeve against the closed end of the bar, a spring associated with said screw and effective therewith to yieldably seat said sleeve against the gage bar and a pitch indication on one of said relatively rotatable members and coperating with the graduations on the other of said members to set o distances.

6. A gage comprising a longitudinally graduated hollow gagebar having a closed end terminating in a reduced extension providing a bearing, a circumferentially graduated sleeve rotatably mounted on said extension and having a reduced bearing against said closed end of the bar said extension having a threaded bore, a screw. set up in said bore, a spring associated with said screw and effective therewith to yieldably seatsaid sleeve' against the closed sleeve and said sleeve having means coperating with the graduations on said bar to set off distances.

7. A gage for setting dividers comprising a longitudinally graduated member and a circumferentially graduated member, said members relatively rotatable and yieldably .comprising a pair of members freely rotatable but not longitudinally movable one on the other and having related scales of graduations, the scale on one member being parallel to the axis of rotation and the scale on the other member being circumferential to said axis, one of said members having a line `inclined to the plane of rotation and cooperating with the scale of the other member to mdicate subdivisions of the spaces between the graduations of the scale parallel to the axis of rotation.

9. A gage comprising a longitudinally graduated member and a circumferentially graduated member, said members relatively rotatable, means for yieldably seating said members against each other, and one of said members having means coperating with the graduations of the other member to set off distances.

l0. A gage for setting dividers and the like comprising a pair of members freely rotatable but not longitudinally movable one on the other and having related scales of graduations, the scale on one member being parallel to the axis of rotation, and that on the other member being circumferential to such axis, the last named member having a continuous line inclined to the plane of rotation and disposed in intersecting relation to the graduations thereof and cooperating with the graduations of the other member to indicate subdivisions of the spaces between the graduations of the scale parallel to the axis of rotation.

l1. A gage comprising a pair ofy members relatively rotatable but longitudinally immovable with relation to each other, said members having scales of related graduations, the scale onone member being parallel to the axis of rotation, and the scale on the other member being circumferential to such axis, one` of said members having a line inclined to the plane ofrotation and cooperating with the scale of the other member to indicate subdivisions of the spaces between the graduations of the scale on said other member.

In testimony whereof I aiiix my signature in presence of two witnesses.

ALEXANDER MELDRUM.

Witnesses:

S. DAVIS, F. G. BoDELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

